Role of levamisole immunotherapy as an adjuvant to radiotherapy in oral cancer--immune responses.

Investigations were carried out to assess the effect of levamisole immunotherapy as an adjuvant to radiotherapy on the immune response of patients with squamous cell carcinoma of the oral cavity. Parameters assessed were leukocyte migration inhibition, response to PPD and oral cancer extract (OCA), lymphocyte transformation to PHA, circulating antibodies to OCA and circulating immune complexes (CIC). Comparisons were made between groups receiving levamisole (L), those receiving placebo (P) and normal controls. The results of a thirty-month follow-up are presented. Radiotherapy resulted in a depression of cell-mediated functions, reduction in antibody titer also showed a gradual increase with time of follow-up. Levamisole, however, appeared to reduce the levels of CIC.